Electric motor and generator having amorphous core pieces being individually accommodated in a dielectric housing

ABSTRACT

A device such as an electric motor, an electric generator, or a regenerative electric motor includes a rotor arrangement and a stator arrangement. The stator arrangement has a dielectric electromagnet housing and at least one energizable electromagnet assembly including an overall amorphous metal magnetic core. The overall amorphous metal magnetic core is made up of a plurality of individually formed amorphous metal core pieces. The dielectric electromagnet housing has core piece openings formed into the electromagnet housing for holding the individually formed amorphous metal core pieces in positions adjacent to one another so as to form the overall amorphous metal magnetic core. The device further includes a control arrangement that is able to variably control the activation and deactivation of the electromagnet using any combination of a plurality of activation and deactivation parameters in order to control the speed, efficiency, torque, and power of the device.

This is a Continuation application of copending prior application Ser.No. 09/111,249 filed on Jul. 3, 1998, which is a continuation ofapplication Ser. No. 08/963,290 filed on Nov. 3, 1997 that issued asU.S. Pat. No. 5,814,914 on Sep. 29, 1998, which is a continuation ofapplication Ser. No. 08/774,946 filed on Dec. 27, 1996 and now issued asU.S. Pat. No. 5,731,649 on Mar. 24, 1998.

BACKGROUND OF THE INVENTION

The present invention relates generally to electric motors, generators,and regenerative motors. The term regenerative motor is used herein torefer to a device that may be operated as either an electric motor or agenerator. More specifically, the invention relates to an electricmotor, generator, or regenerative motor including a stator arrangementwhich itself includes an electromagnet assembly having an amorphousmetal magnetic core made up of a plurality of individually formedamorphous metal core pieces. The present invention also provides acontrol arrangement that is able to variably control the activation anddeactivation of an electromagnet using any combination of a plurality ofactivation and deactivation parameters in order to control the speed,efficiency, power, and torque of the device.

The electric motor and generator industry is continuously searching forways to provide motors and generators with increased efficiency andpower density. For some time now, it has been believed that motors andgenerators constructed using permanent super magnet rotors (for examplecobalt rare earth magnets and Neodymium-Iron-Boron magnets) and statorsincluding electromagnets with amorphous metal magnetic cores have thepotential to provide substantially higher efficiencies and powerdensities compared to conventional motors and generators. Also, becauseamorphous metal cores are able to respond to changes in a magnetic fieldmuch more quickly than conventional ferrous core materials, amorphousmetal magnetic cores have the potential to allow much faster fieldswitching within motors and generators, and therefore allow much higherspeed and better controlled motors and generators than conventionalferrous cores. However, to date it has proved very difficult to providean easily manufacturable motor or generator which includes amorphousmetal magnetic cores.

Amorphous metal is typically supplied in a thin continuous ribbon havinga uniform ribbon width. However, amorphous metal is a very hard materialmaking it very difficult to cut or form easily, and once annealed toachieve peak magnetic properties, becomes very brittle. This makes itdifficult and expensive to use the conventional approach to constructinga magnetic core. This conventional approach typically involves cuttingindividual core layers having a desired shape from a sheet of corematerial and laminating the layers together to form a desired overallmagnetic core shape. The brittleness of amorphous metal also causesconcern for the durability of a motor or generator which utilizesamorphous metal magnetic cores. Magnetic cores are subject to extremelyhigh magnetic forces which change at very high frequencies. Thesemagnetic forces are capable of placing considerable stresses on the corematerial which may damage an amorphous metal magnetic core.

Another problem with amorphous metal magnetic cores is that the magneticpermeability of amorphous metal material is reduced when it is subjectedto physical stresses. This reduced permeability may be considerabledepending upon the intensity of the stresses on the amorphous metalmaterial. As an amorphous metal magnetic core is subjected to stresses,the efficiency at which the core directs or focuses magnetic flux isreduced resulting in higher magnetic losses, reduced efficiency,increased heat production, and reduced power. This phenomenon isreferred to as magnetostriction and may be caused by stresses resultingfrom magnetic forces during the operation of the motor or generator,mechanical stresses resulting from mechanical clamping or otherwisefixing the magnetic core in place, or internal stresses caused by thethermal expansion and/or expansion due to magnetic saturation of theamorphous metal material.

Conventional magnetic cores are formed by laminating successive layersof core material together to form the overall core. However, asmentioned above, amorphous metal is difficult to cut or form easily.Therefore, in the past, amorphous metal cores have often been formed byrolling an amorphous metal ribbon into a coil with each successive layerof the material being laminated to the previous layer using an adhesivesuch as an epoxy. When in use in an electric motor or generator, thislaminated construction restricts the thermal and magnetic saturationexpansion of the coil of amorphous metal material and results in highinternal stresses. These stresses cause magnetostriction that reducesthe efficiency of the motor or generator as described above. Also, thisconstruction places a layer of adhesive between each coil of the core.Since amorphous metal material is typically provided as a very thinribbon, for example only a couple of mils thick, a significantpercentage of the volume of the core ends up being adhesive material.This volume of adhesive reduces the overall density of the amorphousmetal material within the laminated core, and therefore, undesirablyreduces the efficiency of the core to focus or direct the magnetic fluxfor a given volume of overall core material.

The present invention provides a method and arrangement for minimizingthe stresses on an amorphous metal magnetic core in an electric motor,generator, or regenerative motor. This method and arrangement eliminatesthe need for laminating the various layers of the amorphous metalthereby reducing the internal stresses on the material and increasingthe density of the amorphous material within the overall core. Also, inorder to take advantage of the high speed switching capabilities of theamorphous metal magnetic core material, the present invention providescontrol methods and arrangements that are able to variably control theactivation and deactivation of the electromagnet of an electric motor,generator, or regenerative motor device including an amorphous metalmagnetic core by using a combination of a plurality of differentactivation and deactivation parameters in order to control the speed,efficiency, torque, and power of the device.

SUMMARY OF THE INVENTION

As will be described in more detail hereinafter, a device such as anelectric motor, an electric generator, or a regenerative electric motoris disclosed herein. The device includes a rotor arrangement, at leastone stator arrangement, and a device housing for supporting the rotorarrangement and the stator arrangement in the predetermined positionsrelative to one another. The device housing also supports the rotorarrangement for rotation along a predetermined rotational path about agiven rotor axis. The stator arrangement has at least one energizableelectromagnet assembly including an overall amorphous metal magneticcore and an electric coil array which together define at least onemagnetic pole piece. The overall amorphous metal magnetic core is madeup of a plurality of individually formed amorphous metal core pieces.The stator arrangement also includes a dielectric electromagnet housingfor supporting the electromagnet assembly such that the magnetic polepieces are positioned adjacent the rotational path of the rotorarrangement. The dielectric electromagnet housing has core pieceopenings formed into the electromagnet housing for holding theindividually formed amorphous metal core pieces in positions adjacent toone another so as to form the overall amorphous metal magnetic core.

In one preferred embodiment, the rotor arrangement has at least onerotor magnet with north and south poles and the rotor arrangement has anarrangement for supporting the rotor magnet for rotation about a givenrotor axis such that at least one of the magnet's poles is accessiblealong a predetermined rotational path about the given rotor axis. In apreferred embodiment, the rotor magnet is a super magnet.

In some embodiments, the individually formed amorphous metal core piecesare amorphous metal windings formed from a continuous ribbon ofamorphous metal. Preferably, the continuous ribbon of amorphous metalhas a substantially constant ribbon width. The individually formedamorphous metal core pieces may have a variety of cross-sectional shapesincluding a circle, an oval, an egg shape, a toroidal ring, a trianglehaving rounded corners, and a trapezoid having rounded corners.Alternatively, the individually formed amorphous metal core pieces maybe formed from individual strips of amorphous metal material stacked inan associated core piece opening of a core piece housing. Also, in someembodiments, any voids in the core piece openings of the electromagnethousing holding the amorphous metal core pieces are filled with adielectric oil. Additionally, the amorphous metal core pieces may be oilimpregnated.

In one embodiment, the stator arrangement includes a plurality ofelectromagnet assemblies, each having a plurality of pole pieces. Eachof the pole pieces is an individually formed amorphous metal core piece.Furthermore, at least one of the individually formed amorphous metalcore pieces is a toroidal ring forming an electromagnetic yokemagnetically coupling each of the pole pieces to one another. Thetoroidal ring electromagnetic yoke includes an annular or other suchcontinuous surface defined by one continuous edge of the continuousribbon of amorphous metal after the ribbon of amorphous metal has beenwound about itself. Each of the pole pieces of the electromagnetassembly has a first end (defined by one continuous edge of the ribbon)positioned adjacent the predetermined rotational path of the rotormagnet. Also, each of the pole pieces of the electromagnet assembly hasa second end (defined by the other continuous edge of the ribbon)positioned adjacent the annular surface of the toroidal ringelectromagnetic yoke.

In another embodiment, the electromagnet of the stator arrangementincludes a generally U-shaped overall amorphous metal magnetic corehaving two pole pieces. The two pole pieces are each individually formedamorphous metal core pieces. An additional individually formed amorphousmetal core piece forms an electromagnetic yoke magnetically coupling thetwo pole pieces to one another such that the core pieces together definethe U-shaped overall core.

In still another embodiment, the arrangement supporting the rotor magnetsupports the rotor magnet such that both the north and south poles ofthe rotor magnet are accessible along different predetermined rotationalpaths about the given rotor axis. The electromagnet of the statorarrangement includes a generally C-shaped overall amorphous metalmagnetic core having two pole pieces with each of the pole piecespositioned adjacent to a corresponding one of the predeterminedrotational paths of the north and south poles of the rotor magnet. Theoverall magnetic core of the electromagnet assembly is a generallyC-shaped overall amorphous metal magnetic core defining the two polepieces such that each of the pole pieces is positioned adjacent to acorresponding one of the different predetermined rotational paths. Thetwo pole pieces are each individually formed amorphous metal corepieces. Additional individually formed amorphous metal core pieces forman electromagnetic yoke magnetically coupling the two pole pieces to oneanother such that the core pieces together define the C-shaped overallcore.

A method of making an amorphous metal magnetic core for an electromagnetof a device such as an electric motor, an electric generator, or aregenerative electric motor is also disclosed herein. The methodincludes the step of forming a plurality of individually formedamorphous metal core pieces, each having a desired core piece shape. Adielectric magnetic core housing including magnetic core piece openingsthat define the desired overall magnetic core shape is provided. Theplurality of individually formed amorphous metal core pieces areassembled into the core piece openings of the dielectric magnetic corehousing such that the dielectric core housing holds the core piecesadjacent to one another so as to form the desired overall magnetic coreshape. In a preferred method, each core piece is wound into its finalshape from a continuous ribbon of amorphous metal.

In accordance with another aspect of the present invention, a method andarrangement for controlling the rotational speed and input/output powerand torque of a device such as an electric motor, an electric generator,or a regenerative electric motor is disclosed herein. The deviceincludes a rotor supported for rotation along a predetermined rotor pathabout a given rotor axis. Preferably, the rotor includes at least onepermanent super magnet. The device also includes a stator having aplurality of dynamically activatable and deactivatable electromagnetassemblies (also referred to herein merely as electromagnets) withamorphous metal magnetic cores. The electromagnets are spaced apart fromone another adjacent to the predetermined rotor path such that movementof a particular point on the rotor (rotor point) from a given pointadjacent one electromagnet (stator point) to a given point adjacent thenext successive electromagnet (stator point) defines one duty cycle. Aposition detector arrangement determines the position and rotationalspeed of the rotor relative to the stator at any given time in a dutycycle and produces corresponding signals. A controller responsive to thesignals controls the activation and deactivation of the electromagnetsof the stator using predetermined device control settings such that, foreach duty cycle, the controller is able to control any combination of aplurality of activation and deactivation parameters in order to controlthe speed, efficiency, and input/output power and torque of the device.

In a preferred embodiment, the activation and deactivation parametersinclude (i) the duty cycle activation time which is the continuousduration of time in which the electromagnet of the stator is activated(with either one polarity or the other) for each duty cycle, (ii) thestart/stop points of the duty cycle activation time which are the timesat which the duty cycle activation time starts and stops during the dutycycle relative to the rotational position of the rotor as it movesthrough the duty cycle from stator point to the next adjacent statorpoint, and (iii) the modulation of the duty cycle activation time whichis the pulse width modulating of the electromagnet by activating anddeactivating the electromagnet during what would otherwise be thecontinuous duty cycle activation time.

In another embodiment, the position detector arrangement includes anencoder disk supported for rotation with the rotor and also includes anarray of optical sensors arranged in close proximity to the encoderdisk. The encoder disk has a plurality of concentric tracks with spacedapart position indicating openings which are actually through-holes inthe disk. Each of the optical sensors corresponds to and is opticallyaligned with an associated one of the concentric tracks such that eachsensor is able to detect the presence of the position indicatingopenings defining its associated concentric track so as to be able todetect the position of the rotor relative to the stator. Preferablythese openings are sized and positioned to represent a digital byte ofrotor positional information with each track contributing one bit of theoverall digital byte. In this way, during startup of the motor/generatordevice, the position of the rotor can be precisely determined.

In still another embodiment, the controller further includes a counterarrangement capable of counting in increments of time which allow eachduty cycle to be divided into a multiplicity of time periods which thecontroller uses to control when to activate and deactivate theelectromagnet.

In accordance with another aspect of the present invention, a method andarrangement for conditioning the electrical output of an electricgenerator driven by a input drive device is disclosed. The generatorincludes a stator assembly having at least one dynamically activatableand deactivatable stator coil and a rotor assembly. A position detectorarrangement determines the position and rotational speed of the rotorassembly relative to the stator assembly at any given time and producescorresponding signals. A controller responsive to the signals variablycontrols the activation and deactivation of the stator coil such thatthe electrical output of the generator is conditioned to a desiredelectrical output without requiring the use of additional electricalpower conditioning devices. In one embodiment, the input drive device isa wind mill. Furthermore, the controller may use a portion of theelectrical power generated by the generator to drive the generator as anelectric motor. The generator may be driven as an electric motor in away which reduces the amount of resistance the generator places on theinput drive device or in a way which increases the amount of resistancethe generator places on the input drive device.

BRIEF DESCRIPTION OF THE DRAWINGS

The features of the present invention may best be understood byreference to the following description of the presently preferredembodiments together with the accompanying drawings in which:

FIG. 1 is a diagrammatic cross-sectional view of a device designed inaccordance with the present invention including a rotor arrangement, astator arrangement having a stator housing and an overall amorphousmetal magnetic core made up of individually formed amorphous metal corepieces, and a control arrangement having an encoder disk.

FIG. 2 is a diagrammatic plan view of the rotor arrangement of thedevice of FIG. 1.

FIG. 3A is an orthographic diagrammatic view of one embodiment of anoverall amorphous metal magnetic core forming part of the statorarrangement of the device of FIG. 1.

FIG. 3B is a diagrammatic cross-sectional view of the stator housing ofFIG. 1.

FIG. 4 is a diagrammatic plan view of the encoder disk of the device ofFIG. 1.

FIG. 5 is a graph illustrating various activation and deactivationparameters which the control arrangement of the device of FIG. 1 may useto control the device of FIG. 1.

FIG. 6 is a diagrammatic view of one embodiment of the invention inwhich a windmill drives a generator designed in accordance with theinvention.

FIG. 7 is a diagrammatic view of another embodiment of the invention inwhich a turbine engine drives a generator designed in accordance withthe invention.

FIG. 8 is a perspective view of a second embodiment of an overallamorphous metal magnetic core designed in accordance with the presentinvention.

FIG. 9 is a perspective view of a third embodiment of an overallamorphous metal magnetic core designed in accordance with the presentinvention.

FIG. 10 is a perspective view of a fourth embodiment of an overallamorphous metal magnetic core designed in accordance with the presentinvention.

FIGS. 11A-H are diagrammatic perspective views of various embodiments ofthe individual amorphous metal core pieces having variouscross-sectional shapes.

FIG. 12 is a diagrammatic cross-sectional view of a multiphase devicedesigned in accordance with the present invention.

FIG. 13 is a diagrammatic plan view of a stator arrangement of anotherembodiment of a multiphase device designed in accordance with thepresent invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Turning to the drawings, wherein like components are designated by likereference numerals throughout the various figures, attention isinitially directed to FIGS. 1-3B. FIG. 1 illustrates a cross sectionalview of a device 10 designed in accordance with the present. Althoughdevice 10 will be referred to as an electric motor or an electricgenerator at various times throughout this description, it should beunderstood that device 10 may take the form of a motor, a generator, analternator, or a regenerative motor depending on the requirements of theapplication in which the device is used. For purposes of thisdescription, the term regenerative motor refers to a device that may beoperated as either an electric motor or an electric generator. Also,although device 10 will in most cases be described as a DC brushlessmotor, it should be understood that it may take the form of a widevariety of other types of motors and/or generators and still remainwithin the scope of the invention. These other types of motors and/oralternators/generators include, but are not limited to, DC synchronousdevices, variable reluctance or switched reluctance devices, andinduction type motors.

As best shown in FIG. 1, device 10 includes a shaft 14, a rotorarrangement 16, a stator arrangement 18, and a device housing 20. Devicehousing 20 supports shaft 14 for rotation about the longitudinal axis ofthe shaft using bearings 22 or any other suitable and readily providablearrangement for supporting a shaft for rotation. Rotor arrangement 16 isfixed to shaft 14 for rotation with the shaft about the longitudinalrotational axis of shaft 14. Stator arrangement 18 is supported bydevice housing 20 such that the stator arrangement is positionedadjacent the rotational path of the rotor arrangement.

Referring now to FIG. 2, which is a plan view of one preferredembodiment of rotor arrangement 16, rotor arrangement 16 will bedescribed in more detail. In this embodiment, rotor arrangement 16 is adisk or axial type rotor including six radially spaced apart permanentsuper magnets 24a-f (for example cobalt rare earth magnets), each havingopposite ends defining north and south poles. Magnets 24a-f aresupported for rotation about the axis of shaft 14 by a rotor disk 26 orany other suitable arrangement such that the magnetic poles of magnets24a-f are accessible along two predetermined rotational paths about theshaft axis and adjacent the rotor arrangement. They are orientedrelative to one another such that on each side of the rotor disk, themagnets present alternating north and south poles as shown in FIG. 2.

Although magnets 24a-f have been described as being permanent supermagnets, this is not a requirement. Alternatively, the magnets may beother magnetic materials, or, in some cases may be electromagnets. Also,although the rotor arrangement has been described as being a disk oraxial type rotor, this is not a requirement. Instead, the rotor may takeon a wide variety of specific configurations such as a barrel or radialtype rotor with the magnets being positioned on the outer circumferenceof the barrel or radial type rotor. Although the rotor has beendescribed as including six magnets, it should be understood that therotor may include any number of magnets and still remain within thescope of the invention. And finally, although the rotor arrangement hasbeen described as including magnets, this is not a requirement. Forexample, in the case of an induction motor, rotor arrangement 16 wouldnot include magnets 24a-g. Instead, as would be understood by thoseskilled in the art, rotor disk 26 would be constructed from an ironbased material or some other magnetic material to form a magnetic rotorcore which is driven by a rotating magnetic field created by theswitching of the stator arrangement.

As best shown in FIG. 1, in the embodiment being described, statorarrangement 18 includes two stator housings 28a and 28b with the statorhousings being positioned adjacent opposite sides of rotor arrangement16. Stator housings 28a and 28b are mirror images of one another, andtherefore, only stator housing 28a will be described in detail. Statorhousing 28a is formed from a dielectric material such as, but notlimited to, a high strength composite or plastic material. Anyappropriate material may be used to form the stator housing so long asit is dielectric and able to properly support all of the associatedcomponents making up stator arrangement 18.

In accordance with the present invention, stator housing 28a has aplurality of openings including core piece openings 30 and coil openings32 formed into the housing for supporting a dynamically activatable anddeactivatable electromagnet assembly 34. The electromagnet assembly 34includes an overall amorphous metal magnetic core 36 and a coil array38. Coil array 38 is supported in coil openings 32. Also in accordancewith the invention, overall amorphous metal core 36 is made up of aplurality of individually formed amorphous metal core pieces 36a-g someof which form magnetic pole pieces as best shown in FIG. 3A. Statorhousing 28a supports electromagnet assembly 34 such that the pole piecesof the electromagnet assembly are held adjacent to one of thepredetermined rotational paths of the magnetic poles of magnets 24a-f onrotor arrangement 16 as best shown in FIG. 2.

FIG. 3A illustrates the specific configuration of overall amorphousmetal core 36 for the particular embodiment shown in FIG. 1. Eachindividual core piece 36a-g is formed by winding a continuous ribbon ofamorphous metal material into the desired shape. In the case of corepieces 36a-f, the core piece shape is a generally cylindrical shape suchthat the opposing continuous edges of each of these core pieces defineopposite ends 37a and 37b of the core piece. However, in the case ofcore piece 36g, the core piece shape is a toroidal ring having anannular surface 40 defined by one continuous edge of the continuousamorphous metal ribbon wound to form toroidal ring core piece 36g. Ineither case, for this embodiment, the continuous amorphous metal ribbonis not cut, etched, or otherwise machined other than initially cuttingthe continuous ribbon of amorphous metal to the desired length requiredto form the desired core piece shape. Each of the cylindrical shapedcore pieces 36a-f forms a pole piece of overall core 36 with one end 37aof each cylindrical core piece being positioned against annular surface40 of toroidal ring shaped core piece 36g, and the other end 37bprojecting out away from annular surface 40. Toroidal ring core piece36g acts as a magnetic yoke preventing leakage of magnetic flux andmagnetically coupling each of the cylindrical core pieces 36a-f.

FIG. 3B illustrates stator housing 28a apart from, but designed tocontain, core 36 of FIG. 3A. Note specifically the various core pieceopenings 30 and coil openings 32. Stator housing 28a also includescoolant openings 39 and wire raceway openings 41. Using coolant openings39, a coolant fluid may be circulated through stator housing 28a toprevent excessive heat buildup in stator housing 28a, coil array 38, andcore 36. Coolant openings may be formed in any appropriate locationwithin the stator housing in order to provide cooling for the device.Wire raceway openings 41 are used to run wires which interconnect coilarray 38. Although FIG. 3B illustrates one specific configuration of thestator housing which is designed to house the core pieces illustrated inFIG. 3A, it should be understood that the stator housing may take on awide variety of configurations which vary depending on the specific coredesign.

As best shown in FIGS. 1, 3A, and 3B, individually formed core pieces36a-g are supported within core piece openings 30 of stator housing 28asuch that they are held in their respective positions relative to oneanother. Because core piece openings 30 are formed in stator housing 28ato have the proper shape for supporting each of the various individuallyformed core pieces 36a-f, core pieces 36a-f may be formed by winding theamorphous metal ribbon material without laminating the layers of thewinding. This allows each individually formed core piece to thermallyexpand and/or expand due to magnetic saturation, causing the winding toslightly uncoil, without causing internal stress within the overall coreor within any of the individually formed core pieces. This arrangementsubstantially reduces the problems caused by magnetostriction describedin the background of the invention. Also, this arrangement eliminatesthe need to laminate the core pieces and therefore eliminates the volumeof space within the overall core which is taken up by the laminatingmaterial. Because of this, a greater amount of amorphous metal materialis able to be placed into a given volume which improves the efficiencyat which a magnetic core is able to direct or focus magnetic flux. Atthe same time, each stator housing holds the pole pieces 36a-f in directcontact with yoke 36g so that the entire core, from a functionalstandpoint, approximates a single integrally formed core. Stator housing28a may also completely encase overall amorphous metal core 36 creatinga sealed enclosure which prevents corrosion of the core pieces.

In the embodiment shown in FIG. 1, any voids in core piece openings 30that are not filled by core pieces 36a-g are filled with a dielectricoil 42 and core piece openings 30 are sealed to maintain the oil withinthe voids. This oil filling of the core piece openings acts as a cushionto help prevent damage to the amorphous metal material as it issubjected to the large and varying magnetic forces associated with themotor. This oil filling also helps to thermally equalize the statorarrangements and may be used to improve the heat dissipatingcharacteristics of the overall device. Also, amorphous metal core pieces36a-g are oil impregnated. This allows the windings of the amorphousmetal core pieces to more easily expand due to magnetic saturation andthermal expansion of the amorphous metal material further reducingstresses that may cause magnetostriction. Although, the core pieceopenings described above are oil filled and the core pieces are oilimpregnated, this is not a requirement. The invention would equallyapply to devices which use magnetic cores made up of individually formedamorphous metal magnetic core pieces supported in openings of a housingto form an overall amorphous metal magnetic core shape regardless ofwhether or not the openings were filled with oil and the core pieceswere oil impregnated.

Device 10 is a brushless, synchronous device in which the coils makingup electromagnet coil array 38 within state housing 28a are allelectrically connected such that they are activated and deactivated atthe same time. In the embodiment shown in FIG. 1, coil array 38 includessix pole piece coils, two of which are illustrated in FIG. 1 as coils38a and 38d. Coil array 38 may be epoxied or otherwise fixed intoposition in order to add to the overall structural integrity of thestator arrangement. Each coil is positioned around a corresponding oneof core pieces 36a-f, two of which are illustrated in FIG. 1 as corepieces 36a and 36d. Coil array 38 is wound such that the projecting endsof the pole pieces formed by magnetic core pieces 36a-f form alternatingnorth and south poles when coil array 38 is activated. Toroidal ringcore piece 36g acts as a magnetic yoke redirecting the magnetic fluxassociated with the ends of core pieces 36a-f that are adjacent totoroidal ring core piece 36g to the adjacent pole pieces of the oppositepolarity. When the device is operated as an electric motor, switchingthe direction of current flow through coil array 38 reverses thepolarity of each of the pole pieces of electromagnet assembly 34. Aswill be described in more detail hereinafter, in the case of agenerator, switching the way in which the electromagnets are connectedto a load controls the power output and the condition of the electricityproduced by the generator. This arrangement allows the alternating northand south poles of electromagnet assembly 34 of stator arrangement 18 tocontrollably interact with the alternating north and south poles ofpermanent magnets 24a-f of rotor arrangement 16.

Device 10 also includes a control arrangement 44 for activating anddeactivating coil array 38 with alternating polarity. Controlarrangement 44 includes a controller 46 which may be any suitable andreadily providable controller that is capable of dynamically activatingand deactivating electromagnet assembly 34 with varying polarity.Preferably, controller 46 is a programmable controller capable ofactivating and deactivating electromagnet assembly 34 at a rate of speedmuch higher than is typically done in conventional electric motors andgenerators. Because of the inherent speed at which the magnetic fieldmay be switched in an amorphous metal core, for each duty cycle of thedevice, the stator arrangement of device 10 allows controller 46 to useany combination of a plurality of activation and deactivation parametersto control the rotational speed, power, and torque output of device 10.For purposes of this description, one duty cycle is defined as themovement of a particular point of the rotor from a given stator pointadjacent one electromagnet pole piece of the stator arrangement to agiven stator point adjacent the next successive electromagnet pole pieceof the stator arrangement, as mentioned previously.

Still referring to FIG. 1, control arrangement 44 also includes aposition detector arrangement 48 for determining the position androtational speed of rotor arrangement 16 relative to stator arrangement18 at any given time for each duty cycle and for producing correspondingsignals. Detector arrangement 48 includes an encoder disk 50 supportedon shaft 14 for rotation with rotor arrangement 16. Detector arrangement48 also includes an array of optical sensors 52 positioned adjacent theencoder disk.

As illustrated in FIG. 4, which is a plan view of encoder disk 50,encoder disk 50 includes a plurality of concentric tracks 54 withposition indicating openings 56 formed into each of the tracks. In thisembodiment, disk 50 includes six concentric tracks 54a-f. Disk 50 isdivided into three one hundred and twenty degree arc, pie shapedsections 58, each of which are identical to one another. Each section 58is associated with a pie shaped section of the rotor arrangementextending from a given point on a first rotor magnet having a particularpolarity to a corresponding point on the next successive magnet havingthe same polarity (i.e. from one south pole past a north pole to thenext south pole). Inner track 54a has one long opening 56a extendinghalf (a sixty degree arc) of the length of track 54a in each section 58.In this case, each of these openings corresponds to one duty cycle ofthe device and the three openings together are aligned with every otherone of the six rotor magnets (i.e. the three magnets having the samepolarity on each given side of the rotor disk). Within each section,each successive track has twice as many openings which are half as longas the openings in the previous track. That is track 54b has twoopenings 56b within each section, track 54c has four openings 56c and soon with the outside track having thirty two openings, each having an arcof one and seven eighths of a degree.

Optical sensor array 52 includes six optical sensors with each sensorcorresponding to and positioned in optical alignment with one of theconcentric tracks on encoder disk 50. Array 52 is positioned adjacentencoder disk 50 such that optical sensors detect the presence ofopenings 56. With each of the optical sensor providing one bit ofinformation, array 52 is able to provide controller 46 with a binaryword (a byte) which identifies the position of the rotor arrangementwithin less than a two degree arc. Using the most significant bit, thatis the sensor associated with track 54a, controller 46 is also able todetermine the location of the alternating north and south poles of themagnets since the openings 56a of track 54a corresponds to every othermagnet on the rotor disk as described above.

Controller 46 also includes a counter arrangement 49 capable of countingin increments of time which allow each duty cycle (sixty degree arc) tobe divided into a multiplicity of time periods or counts, for example,1600 counts per duty cycle when the device is rotating at apredetermined maximum speed. This corresponds to one hundred counts foreach opening 56f, or, in other words, one hundred times the resolutionprovided by the encoder disk. For illustrative purposes, for a highspeed motor capable of operating at 20,000 RPM, this would require acounter arrangement or clock capable of operating at 3.2 million countsper second or a 3.2 MHz clock. Although only one specific clock speedhas been described in detail, it should be understood that the presentinvention would equally apply regardless of the specific clock speed ofthe counter arrangement.

Controller 46 is arranged to be able to activate or deactivateelectromagnet assembly 34 at any predetermined count of counterarrangement 49. This provides extremely precise control of theactivation and deactivation of the electromagnets. Although the exampleof an operating speed of 20,00 RPM is used, it is to be understood thatthis is not an upper limit. Because of the extremely fast switchingcapability of the amorphous metal stator arrangement and the preciseactivation and deactivation control of the electromagnets provided bythe control arrangement described above, motor and generator devicesdesigned in accordance with the invention are capable of providingextremely high speed devices with rotational speeds of 50,000 RPM oreven greater than 100,000 RPM. The present invention also provides astator arrangement configuration and rotor arrangement configurationthat are capable of withstanding the extreme centrifugal forces thatwould be generated by these extremely high speed devices.

In order to allow controller 46 to discretely detect the presence of theopenings of the various tracks in encoder disk 50, the openings in thevarious tracks are slightly staggered relative to one another such thatthe different optical sensors of array 52 are not trying to indicate thedetection of the beginning of an opening for different tracks at thesame precise time. This encoding configuration is commonly referred toas gray code and is intended to prevent errors by the controller causedby very slight inaccuracies in the locations of the position indicatingopenings.

Referring back to FIG. 1, now that the various components making updevice 10 have been described, the operation of the device in variousmodes will be described in more detail. Because the amorphous metalmagnetic core material is able to switch it's magnetic field extremelyquickly and because control arrangement 44 is able to activate anddeactivate electromagnet assembly 34 at extremely precise times, controlarrangement 44 of the present invention allows controller 46 to use anycombination of a plurality of electromagnet assembly activation anddeactivation parameters in order to control the speed, efficiency,torque, and power of the device. These parameters include, but are notlimited to, the duty cycle activation time, the start/stop points of theduty cycle activation time, and the modulation of the duty cycleactivation time. The activation and deactivation parameters will bedescribed in more detail with reference to FIGS. 5A-C, which are graphsshowing the activation/deactivation status of electromagnet assembly 34for two consecutive duty cycles D1 and D2.

The electromagnet assembly is activated having alternating north andsouth polarity for each of the pole pieces making up the electromagnetassembly. For any given stator pole piece, duty cycle D1 corresponds tothe time it takes for the rotor assembly to rotate from a point where anorth pole of one of the rotor magnets is adjacent to and lined up topdead center with the given stator pole piece to the time the south poleof the next successive rotor magnet is adjacent to and lined up top deadcenter with the given stator pole piece. As indicated by the referenceletter N, the electromagnet assembly is activated during duty cycle D1such that the given stator pole piece acts as a north pole. Duty cycleD2 corresponds to the time it takes for the rotor assembly to rotatefrom the point where the south pole of the rotor magnet at the end ofduty cycle D1 is lined up top dead center with the given stator polepiece to the time the north pole of the next successive rotor magnet islined up top dead center with the given stator pole piece. As indicatedby the reference letter S, the electromagnet assembly is activatedduring duty cycle D2 such that the given stator pole piece acts as asouth pole.

As shown in FIG. 5A, the duty cycle activation time is the continuousduration of time in which the electromagnet assembly 34 of the statorarrangement is activated for a given duty cycle. The duty cycleactivation time is indicated by the letter T in FIGS. 5A-C. Thestart/stop points of the duty cycle activation time are the times atwhich the duty cycle activation time starts (indicated by referencenumeral 60) and stops (indicated by reference numeral 62) during theduty cycle relative to the rotational position of the rotor. Asillustrated in FIG. 5B, the start/stop time may be changed while keepingthe duty activation time T constant or it may be changed while, at thesame time, changing the length of duty activation time T. And finally,the modulation of the duty cycle activation time is the pulse widthmodulating of electromagnet assembly 34 during the duty activation timeT between its start and stop points. As illustrated in FIG. 5C, this isdone by activating and deactivating electromagnet assembly 34 duringwhat would otherwise be the continuous duty cycle activation time T.While the pulse width modulation is shown as equal ON and OFF pulses,the ON pulses may be different in duration than the OFF pulses.Furthermore, each set of pulses can vary among themselves to provide adesired overall activation time within the time T. In accordance withthe invention, the speed, efficiency, and power and torque input/outputof device 10 may be controlled by using control arrangement 44 toactivate and deactivate electromagnet assembly 34 using any combinationof these parameters, or any other predetermined activation anddeactivation parameters in some combination.

When device 10 is stopped, controller 46 uses encoder disk 50 andoptical sensor array 52 to determine the relative position of rotorarrangement 16 relative to stator arrangement 18. In the case of anelectric motor, controller 46 uses the position information to start therotation of the rotor arrangement by energizing electromagnet assembly34 such that pole pieces 36 have the appropriate polarity to start therotation of the motor in the desired direction. Controller 46 activatesand deactivates electromagnet assembly 34 such that the polarity of eachpole piece reverses for each successive duty cycle. Once the motor isrotating at a sufficient speed, controller 46 only uses the outer tracksof encoder disk 50 to determine the rotational speed of the rotorassembly relative to the stator assembly for calibrating counterarrangement 49. Controller 46 continues controlling device 10 by usingcounter arrangement 49 and the signals produced by encoder disk 50 toselect and use predetermined device control settings which may beprogrammed into or otherwise provided to controller 46 to control theactivation and deactivation of electromagnet assembly 34. Becausecontrol arrangement 44 is able to activate or deactivate electromagnetassembly 34 at any one of the counts of counter arrangement 49, controlarrangement 44 is able to very precisely control the speed, efficiency,torque, and power of device 10 using any combination of the abovedescribed activation and deactivation parameters.

The precision, speed, and flexibility of control arrangement 44 allows adevice designed in accordance with the present invention to be used fora wide variety of applications. Also, by using super magnets in therotor assembly and amorphous metal magnetic cores, the device is capableof very high power densities and very high rotational speeds compared toconventional electric motors and generators. These advantages allow adevice designed in accordance with the present invention to be used inways that have not been previously possible or practical usingconventional devices.

In a first example, one preferred embodiment of the invention is anelectric motor for use in a numeric control machine tool application inwhich multiple tools are driven using the same spindle and chuck. In thecase where the electric motor directly drives the spindle and the motorand spindle are supported for movement over a work surface, the spindleand overall tool would not need to be constructed nearly as heavilybecause of the light weight and high power density of the motor. Also,because of the flexibility of the control arrangement of the motor, themotor may be programmed for a wide variety of specific operations. Forinstance, the tool may initially be used as a high speed, relatively lowpower router rotating at for example 20,000 RPM. Then, by driving themotor in the opposite direction, the motor and spindle may be stoppedvery quickly so that a different tool may be automatically inserted intothe chuck. If, for example, the next operation is a lower speed, buthigher power requirement drilling operation, the control arrangement ofthe motor may be programmed to provide the desired speed, efficiency,power, and torque output. Using a motor in accordance with the presentinvention, a much wider range of motor speed, power, and torque settingsare available compared to conventional motors.

In another application illustrated in FIG. 6, device 10 is used as agenerator which is driven by a windmill 100. In this situation, controlarrangement 44 is configured to switch the way electromagnet assembly 34is activated and deactivated in order to vary the power generated bydevice 10 depending on the power input available from windmill 100. Thisarrangement allows the generator to operate in a much wider range ofoperating conditions than is possible using conventional generators.

Typically windmill generators are configured to have a predeterminedelectrical output. As the wind comes up, the generator is not able tooperate until the wind speed reaches a minimum operating speed. Sincetypical windmills are designed to operate at a point near the averagewind speed for the area in which they are installed, this means that thewindmill is not able to generate any power when the wind is below theminimum operating speed of the windmill. As the wind increases beyondthe designed operating speed, the windmill must be feathered or have abreaking mechanism to waste some of the wind energy in order to preventthe windmill from over speeding. In some cases, the windmill must beshut down altogether in very high wind situations to avoid damage orover heating of the breaking mechanism. Therefore, in high windsituations or very high wind situations, much or all of the availablewind energy goes to waste because the windmill generator is only able togenerate its predetermined electrical output.

In accordance with the invention, device 10 may be designed to have amaximum power output which is more in line with the high wind energyavailable to the windmill rather than the average wind energy. In thissituation, when the wind is at it's average wind speed, controlarrangement 44 connects and disconnects electromagnet assembly 34 suchthat device 10 has a power output substantially lower than it's maximumpower output. In fact, in low wind situations, device 10 may be used asan electric motor in order to get the windmill started. Once rotating atan appropriate speed, device 10 may be operated as a generator with avery low power output. As the wind increases to higher than average windspeeds, control arrangement 44 simply activates and deactivateselectromagnet assembly 34 such that the power output increases to matchthe energy input of the wind. In very high wind situations in which thewind energy is even greater than the maximum power output of device 10,device 10 may be operated a certain fraction of the time as an electricmotor driving the windmill in the opposite direction to act as a brake.This overall configuration allows the windmill to operate and produceoutput in a much wider range of wind conditions than is possible usingconventional generators.

The power output of device 10 is controlled by activating anddeactivating electromagnet assembly 34 as described above. Anycombination of activation and deactivation parameters including the dutycycle activation time, the start/stop points of the duty cycleactivation time, and the modulation of the duty cycle activation timemay be used to control the power output of device 10. By controllingthese activation and deactivation parameters, a very wide range of poweroutputs may be achieved for any given sized device. Also, because device10 may be driven in either direction as an electric motor by energizingelectromagnet assembly 34 with the appropriate polarity for any desiredfraction time during it's operation, the device is able to reduce orincrease the amount of force required to turn the device as a generator.Therefore, the device is able to act as a generator with an extremelywide range of power outputs.

When device 10 is acting as a generator, the flexibility provided bycontrol arrangement 44 also allows device 10 to be arranged to conditionthe power output of device 10 without requiring the use of additionalpower conditioning devices. Using the example of the windmillapplication illustrated in FIG. 6, as described above, controlarrangement 44 is able to activate and deactivate electromagnet assembly34 in order to control the power output of device 10. Because of thiscontrol arrangement 44 is able to control the speed at which thewindmill operates. Also, control arrangement 44 is able to control theactivation and deactivation parameters as described above. This allowscontrol arrangement 44 to be configured to activate and deactivate theelectromagnet assembly such that the output of device 10 is conditionedto a desired electrical output without requiring the use of additionalelectrical power conditioning devices. This is done by controlling thespeed of the device and activating and deactivating the electromagnetassembly at the appropriate times to create an electrical outputconditioned to a desired electrical output. In the case where the outputis desired to be pulsed DC, as would be the case when chargingbatteries, an H bridge controller can convert the AC output of thedevice to pulsed DC. This is known as "active rectification".

As illustrated in FIG. 7, another application in which the inventivedevice is well suited is a gas turbine driven generator application.Because of the extremely high rotational speeds of turbine engines,conventional generators are typically connected to a turbine engineusing reduction gears that substantially reduce the rotational speed atwhich the generator is driven by the turbine engine. These reductiongear arrangements increase the cost of the overall system and causeenergy loses that reduce the overall efficiency of the combination. Inaccordance with the present invention, a generator designed as describedabove is directly driven by a gas turbine without the use of reductiongears or any other arrangement for reducing the rotational speed atwhich the turbine engine drives the generator. As shown in FIG. 7,device 10 is directly driven by turbine engine 200. Device 10 may alsobe used as a starter motor for the turbine engine. As also describedabove, because of the extremely high speed at which the amorphous metalmagnetic core of device 10 is able to respond to changes in the magneticfield, and because of the extremely fast switching capabilities ofcontrol arrangement 44, device 10 is able to operate effectively atextremely high rotational speeds. This allows device 10 to be directlydriven by turbine engine 200, and eliminates the need for any reductiongears or other arrangements for reducing the rotational speed at whichthe turbine engine drives device 10.

The disk or axial type device configuration described above provides acompact overall package which may be designed to withstand extremelyhigh centrifugal forces. This allows a device of this configuration tooperate at extremely high rotational speeds and therefore offer anextremely high power output for a given size device. In one particularlyinteresting application, the device is contemplated to be used as anelectric motor to directly drive a refrigeration unit turbo compressorat extremely high rotational speeds. These rotational speeds may be50,000 to 100,000 RPM or more. By operating the turbo compressor atthese rotational speeds, the efficiency of the compressor issubstantially improved. Using conventional electric motors which operateat much slower speeds, most or all of the efficiency gain associatedwith the high speed turbo compressor is lost to mechanical losesassociated with the gearing necessary to achieve the high rotationalspeed. By directly driving the compressor with a high speed motordesigned in accordance with the invention, the efficiency lossesassociated with the conventional gear assembly are eliminated. Thisprovides an overall arrangement that is substantially more efficientthan conventional arrangements.

Although the overall amorphous metal magnetic core 36 of device 10 hasbeen described as having an overall shape of a toroidal ring with poleprojections projecting out from one of the annular surfaces of the ringas illustrated in FIG. 3A, this is not a requirement. Instead, theoverall amorphous metal magnetic core may take any desired shape andstill fall within the scope of the invention so long as the overallamorphous metal core is made up of a plurality of individually formedamorphous metal core pieces which are supported adjacent one another bya core housing.

Referring to FIG. 8, the overall amorphous metal core may take the formof U-shaped overall amorphous metal cores. In one specific embodiment,three separate U-shaped overall cores 300 replace the toroidal ringconfiguration shown in FIG. 3A. Each core 300 is made up of threeindividually formed amorphous metal core pieces 300a-c. Core pieces 300aand 300b are cylindrical core pieces similar to core pieces 36a-f ofFIG. 3A. However, core pieces 300c are core pieces having an elongatedoval cross-sectional shape. In this embodiment, the stator housing wouldhave core piece openings arranged such that each pair of core pieces300a and 300b are held adjacent an associated one of core pieces 300c.The electromagnet coil array for this embodiment would be similar tothat described above for device 10. The only difference between theconfiguration described above using the toroidal ring core piece and theU-shaped configuration is that the toroidal ring configurationmagnetically couples all six of the pole pieces formed by core pieces36a-f, whereas, in the U-shaped configuration, only each associated pairof pole pieces formed by core pieces 300a and 300b are magneticallycoupled.

FIG. 9 illustrates another possible configuration for providing themagnetic core of the present invention. As described above, device 10 ofFIG. 1 includes two stator arrangements including overall amorphousmetal cores 36, one on each side of rotor arrangement 16. FIG. 9illustrates a generally C-shaped overall amorphous metal core 400including five individually formed amorphous metal core pieces 400a-e.The two toroidal ring overall cores of FIG. 1 may be replaced with sixoverall amorphous metal cores 400 positioned radially around the rotorarrangement. In this embodiment, six core pieces 400a form pole piecessimilar to pole pieces 36a-f on one side of the rotor arrangement. Corepieces 400b form corresponding pole pieces positioned on the other sideof the rotor arrangement. For each C-shaped overall amorphous metalmagnetic core 400, core pieces 400c-e form a magnetic yoke thatmagnetically couples their associated core pieces 400a and 400b. Also,in this embodiment, the stator housing would be configured to supportall of the various core pieces in their respective positions to form thesix overall C-shaped magnetic cores. As described above with respect tothe U-shaped cores, the only difference between this embodiment and theembodiment of FIG. 1 is that instead of all of the pole pieces on oneside of the rotor arrangement being magnetically coupled by the toroidalring core piece, each pair of pole pieces formed by associated corepieces 400a and 400b on opposite sides of the rotor arrangement aremagnetically coupled.

FIG. 10 illustrates yet another possible configuration for providing themagnetic core of the present invention. In this case the device takesthe form of a barrel or radial type device rather than a disk or axialtype device. In this configuration, a rotor assembly 500 would take theform of a barrel rather than a disk. In this example, if the device is aDC brushless type motor, rotor assembly 500 would included six rotormagnets 502 attached to the outer circumferential edge of the rotorassembly. Alternatively, if the device is an induction type motor,magnets 502 would not be included and rotor assembly 500 would be madeup of an appropriately formed iron based material or other magneticmaterial core.

The stator arrangement of this barrel type embodiment includes only oneoverall amorphous metal core in the form of a generally tubular shapedoverall amorphous metal core 504. Core 504 is made up of a tubularshaped, individually formed amorphous metal core piece 504a and sixindividually formed amorphous metal core pieces or teeth 504b-g. Corepiece 504a is formed by rolling a continuous ribbon of amorphous metalmaterial of a desired width into the desired diameter tube shape. Corepieces 504b-g may be formed by either stacking individual strips ofamorphous metal material to form the desired core piece shape oralternatively may be formed by winding a continuous amorphous metalribbon into a very elongated oval shape. In this embodiment, a statorhousing 506 has core piece openings arranged such that each of corepieces 504b-g are held adjacent to the inner surface of core piece 504a.The electromagnet coil array for this embodiment would be similar tothat described above for device 10. The only difference between theconfiguration described above using the toroidal ring core piece andthis barrel or radial configuration is that, for the barrelconfiguration, the coils would be very elongated coils runninglongitudinally parallel with the axis of the rotor assembly andpositioned around each of the core pieces or teeth 504b-g.

Although the various core pieces have been described throughout thedescription as having specific cross-sectional shapes, it should beunderstood that the invention is not limited to these specificcross-sectional shapes. Instead, as illustrated in FIGS. 11A-F, theindividually formed core pieces may have any cross-sectional shapeincluding a circle, an oval, an egg shape, a toroidal ring, a trianglehaving rounded corners, or a trapezoid having rounded corners asillustrated by core pieces 510, 512, 514, 516, 518, and 520 in FIGS.11A-F respectively.

Although the core pieces have been described as being wound from acontinuous ribbon of amorphous metal material, this is not arequirement. Alternatively, the core pieces may be formed by stackingindividually formed strips or pieces of amorphous metal to form a corepiece of a desired shape such as a rectangular core piece 522 or atrapezoidal cross-sectional shaped core piece 524, as illustrated inFIGS. 11G and 11H, or a wide variety if other particular cross-sectionalshapes. As illustrated in these figures, the individual strips may bestacked atop one another with each piece being the same size and shapeas indicated in FIG. 11G. Alternatively, the individual strips may bestacked beside one another with various individual pieces havingdifferent sizes and shapes as illustrated in FIG. 11H. These variousapproaches allow a wide variety of shapes to be formed.

As is known to those skilled in the art, when amorphous metal materialis produced, it typically has a particular direction along whichmagnetic flux will be directed most efficiently. For a ribbon ofamorphous metal material, this direction is typically either along thelength of the ribbon or across the width of the ribbon. By using theappropriate approach described above to form each of the core pieces ofan overall amorphous metal core, the individual core pieces may beformed such that the amorphous metal material is always oriented suchthat the magnetic flux is directed through the pieces along thedirection of the amorphous metal material that most efficiently directsthe magnetic flux. For example, in the case of the toroidal ringembodiment of FIG. 3A, toroidal ring core piece 36g would be made bywinding an amorphous metal ribbon which has its most efficient fluxdirection aligned along the length of the ribbon. However, each of polepieces 36a-f would be formed by winding an amorphous metal ribbon whichhas its most efficient flux direction aligned across the width of theribbon. This configuration aligns the amorphous metal material such thatthe magnetic flux is directed through the core along the direction ofthe material that most efficiently directs the magnetic flux.

Although the invention has been described as a single phase device inwhich all of the electromagnets of the stator assembly are activatedsimultaneously, this is not a requirement. As would be clear to oneskilled in the art, the device of the invention may also take the formof a multiphase device. FIG. 12 illustrates one approach to providing amultiphase electric motor 600. In this embodiment, three devices 10a-cdesigned as described above for device 10 are mounted in line on acommon shaft. Each of the devices 10a-c is rotated twenty degreesrelative to the previous device. In other words, device 10b is rotatedtwenty degrees relative to device 10a such that each of the pole piecesof the stator arrangement in device 10b is fixed in a position twentydegrees in advance of the corresponding pole pieces of the statorarrangement of device 10a. The same is true for device 10c relative todevice 10b. Since the duty cycle of devices 10a-c can extend through asixty degree arc as described earlier, this configuration causes thethree devices to be out of phase with one another by one third of theirduty cycle. Thus, the three devices 10a-c may be operated as an overallthree phase device with each of the devices 10a-c corresponding to onephase.

Alternatively, as illustrated in FIG. 13, a three phase device may beprovided by constructing a device which includes a stator arrangementhaving an electromagnet assembly 700 made up of individually formed corepieces and three separately controllable coil arrays. In this example,the rotor assembly (not shown in FIG. 13) would still have six rotormagnets as was the case for device 10 of FIG. 1. Similarly, the deviceincludes two stator arrangements with one positioned on each side of therotor arrangement as was also the case for device 10 of FIG. 1. However,as shown in FIG. 13, which is a plan view of electromagnet assembly 700,this electromagnet assembly includes an overall amorphous metal core 702made up of nineteen individually formed amorphous metal core pieces702a-s. A first core piece 702a of the nineteen core pieces is atoroidal ring core piece similar to core piece 36g shown best in FIG. 3.Eighteen core pieces 702b-s are individually wound core pieces havingone end positioned adjacent toroidal ring core piece 702a therebyforming eighteen pole projections. Electromagnet assembly 700 alsoincludes three separately controllable coil arrays 704a-c. Each of theseparately controllable coil arrays is similar to coil array 38 of FIG.1 with each array including a coil wrapped around every thirdconsecutive one of core pieces 702b-s. With this arrangement, each coilarray corresponds to one of the phases of a three phase device.

Although the device has been described above as a three phase device, itshould be understood that the device may alternatively be provided as atwo phase device. In this case, overall amorphous metal core 702 wouldinclude thirteen core pieces rather than nineteen core pieces withtwelve of the core pieces forming pole pieces and one core piece actingas the magnetic yoke as described above. Also, the two phase devicewould include only two individually controllable coil arrays.Furthermore, it is to be understood that the multiple phase devices arenot limited to the toroidal ring core configuration described above.Instead, the core configuration may take on a wide variety ofconfigurations and still remain within the scope of the invention.

Although the above described embodiments have been describe with thevarious components having particular respective orientations, it shouldbe understood that the present invention may take on a wide variety ofspecific configurations with the various components being located in awide variety of positions and mutual orientations and still remainwithin the scope of the present invention. For example, although eachstator arrangement of device 10 was described as including six polepieces and the rotor was described as including six magnets, this is nota requirement. Instead, the stator arrangement may have any desirednumber of pole pieces and the rotor any number of magnets and stillremain within the scope of the invention.

Additionally, the present invention would equally apply to a widevariety of electric motors and generators so long as the statorarrangement of the device included an overall amorphous metal core madeup of individually formed core pieces which are supported in place by adielectric housing. These various generators and motors include, but arenot limited to, motors and generators of the DC brushless type, DCsynchronous type, variable reluctance or switched reluctance type,induction type, and many other types of generators, motors, andalternators. Therefore, the present examples are to be considered asillustrative and not restrictive, and the invention is not to be limitedto the details given herein, but may be modified within the scope of theappended claims.

What is claimed is:
 1. A device selected from the group of devicesconsisting of an electric motor, an electric generator, and aregenerative electric motor, the device including a rotor arrangement,at least one stator arrangement, and a device housing for supporting therotor arrangement and the stator arrangement in predetermined positionsrelative to one another and for supporting the rotor arrangement forrotation along a predetermined rotational path about a given rotor axis,the stator arrangement comprising:a) at least one energizableelectromagnet assembly including an overall amorphous metal magneticcore and electric coil array which together define at least one magneticpole piece, the overall amorphous metal magnetic core being made up of aplurality of individually formed amorphous metal core pieces; and b) adielectric electromagnet housing for supporting the electromagnetassembly such that the magnetic pole pieces are positioned adjacent therotational path of the rotor arrangement, the dielectric electromagnethousing having core piece openings formed into the electromagnet housingfor holding the individually formed amorphous metal core pieces inpositions adjacent to one another so as to form the overall amorphousmetal magnetic core.
 2. A device according to claim 1 wherein the rotorarrangement includes at least one rotor magnet having north and southpoles, the rotor arrangement including means for supporting the rotormagnet for rotation about a given rotor axis such that at least one ofthe magnet's poles is accessible along the predetermined rotational pathabout the given rotor axis.
 3. A device according to claim 2 wherein therotor magnet is a rare-earth permanent magnet.
 4. A device according toclaim 1 wherein any voids in the core piece openings of the dielectricelectromagnet housing holding the amorphous metal core pieces are filledwith a dielectric oil.
 5. A device according to claim 1 wherein at leastsome of the individually formed amorphous metal core pieces areamorphous metal windings formed from a continuos ribbon of amorphousmetal.
 6. A device according to claim 5 wherein the continuous ribbon ofamorphous metal has a substantially constant ribbon width.
 7. A deviceaccording to claim 5 wherein the amorphous metal core pieces are oilimpregnated.
 8. A device according to claim 1 wherein the device is amultiple phase device.
 9. A device according to claim 8 wherein themultiple phase device is made up of a plurality of discrete devicesmounted in line on a common shaft with each of the devices being fixedto one another such that the respective stator arrangements of theplurality of devices are held in positions that are rotated apredetermined angle about the given rotor axis relative to one another.10. A device according to claim 1 wherein the dielectric electromagnethousing further includes coolant openings formed into the electromagnethousing for allowing a coolant fluid to be circulated through thehousing.
 11. A device according to claim 1 wherein the dielectricelectromagnet housing further includes wiring raceway openings formedinto the electromagnet housing for containing wires which interconnectthe coil array.
 12. A device according to claim 1 wherein the device isan induction motor.
 13. A stator arrangement for use in a deviceselected from the group of devices including an electric motor, anelectric generator, and a regenerative electric motor, the deviceincluding said stator arrangement, a rotor arrangement, and a devicehousing for supporting the rotor arrangement and the stator arrangementin predetermined positions relative to one another and for supportingthe rotor arrangement for rotation along a predetermined rotational pathabout a given rotor axis, the stator arrangement comprising:a) at leastone energizable electromagnet assembly including an overall amorphousmetal magnetic core and an electric coil array which together define oneor more magnetic pole pieces, the overall amorphous metal magnetic corebeing made up of a plurality of individually formed amorphous metal corepieces; and b) a dielectric electromagnet housing for supporting theelectromagnet assembly such that the one or more magnetic pole piecesare positionable adjacent the rotational path of the rotor arrangement,the dielectric electromagnet housing having core piece openings formedinto the electromagnet housing for holding the individually formedamorphous metal core pieces in positions adjacent to but unconnectedfrom one another so as to form the overall amorphous metal magneticcore.
 14. A stator arrangement according to claim 13 wherein said corepieces include at least one pole piece having first and second ends anda yoke which are held within said housing openings such that the firstend of said pole piece is positioned adjacent to and in confrontingrelationship with said yoke and the second end project out therefrom.15. A stator arrangement according to claim 13 wherein said core piecesinclude a plurality of pole pieces each having first and second ends anda yoke, all of which are held within said housing openings such that thefirst end of each said pole pieces is position adjacent to and inconfronting relationship with said yoke and the second end of each polepiece projects out therefrom.
 16. A stator according to claim 15 whereineach of said pieces is an amorphous metal winding formed from acontinuous ribbon of amorphous metal having opposite edges such thatsaid opposite edges form the first and second ends of the pole piece.17. A stator according to claim 16 wherein said yoke is an amorphousmetal winding formed from a continuous ribbon of amorphous metal havingopposite edges which define opposite yoke surfaces and wherein the firstend of each of said pole pieces is held by said housing adjacent to andin confronting relationship with one of said yoke surfaces.
 18. A statoraccording to claim 15 wherein at least some of the individually formedamorphous metal core pieces are made a of a stack of individual stripsof amorphous metal material cut to form a predetermined shape.
 19. Anamorphous metal core for use as part of a stator arrangement which inturn can be used in a device selected from the group of devicesincluding an electric motor, an electric generator, and a regenerativeelectric mower, the device including said stator arrangement, a rotorarrangement, and a device housing for supporting the rotor arrangementand the stator arrangement in predetermined positions relative to oneanother and for supporting the rotor arrangement for rotation along apredetermined rotational path about a given rotor access, the amorphousmetal core comprising:a) a plurality of individually formed amorphousmetal core pieces including one or more thereof which serve as polepieces when combined with cooperating electric coils; and b) adielectric electromagnet housing for supporting the core pieces inadjacent unconnected relationship with one another such that the one ormore magnetic pole pieces which are formed when combined with thecooperating electric coils are positionable adjacent the rotational pathof the rotor arrangement, the dielectric electromagnet housing havingcore piece openings formed into the electromagnet housing for hold theindividually formed amorphous metal core pieces in said adjacent butunconnected relationship with one another.
 20. An amorphous metal coreaccording to claim 19 wherein said core pieces include at least one polepiece having first and second ends and a yoke which are held within saidhousing openings such that the first end of said pole piece ispositioned adjacent to and in confronting relationship with said yokeand the second end projects out therefrom.
 21. A method of making anoverall amorphous metal magnetic core for an electromagnet assembly of adevice selected from the group of devices consisting of an electricmotor, an electric generator, and a regenerative electric motor, themethod comprising the steps of:a) forming a plurality of individuallyformed amorphous metal core pieces, each having a desired core pieceshape; b) providing a dielectric magnet core housing including magneticcore piece openings that define the desired overall magnetic core shape;and c) assembling the plurality of individually formed amorphous metalcore pieces into the core piece openings of the dielectric magnetic corehousing such that the dielectric core housing holds the core piecesadjacent to one another so as to form the desired overall magnetic coreshape.
 22. A method according to claim 21 further including the step offilling any voids in the core piece openings of the magnetic corehousing with a dielectric oil.
 23. A method according to claim 21wherein the step of forming a plurality of individually formed amorphousmetal core pieces having a desired core piece shape includes the step offorming at least some of the amorphous metal core pieces by winding acontinuous ribbon of amorphous metal material into a coil having adesired cross-sectional shape.
 24. A method according to claim 23wherein the step of forming a plurality of individually formed amorphousmetal core pieces having a desired core piece shape includes the step ofoil impregnating the amorphous metal core pieces.
 25. A method accordingto claim 23 wherein the continuous ribbon of amorphous metal material isnot cut, etched, or otherwise machined other than cutting the continuousribbon of amorphous metal material to the desired length.
 26. A methodaccording to claim 21 wherein the step of forming a plurality ofindividually formed amorphous metal core pieces having a desired corepiece shape includes the step of forming at least some of theindividually formed amorphous metal core pieces by stacking individualstrips of amorphous metal material cut to form a desired shape to formthe core piece.